1. Field of the Invention
The invention concerns a latching mechanism for a cartridge door such as the visor-like door of a videocassette of the VHS or Betamax format.
2. Description of the Related Art
The visor-like door of a VHS or Betamax videocassette is spring-loaded to open when a latch is depressed upon contacting a finger of the recorder. Originally, the latching mechanism for each of those videocassettes had two pieces, typically a molded plastic latch plate and a metal spring. The recently issued U.S. Pat. No. 4,475,700 (MacLeod et al.) discloses such a 2-piece door-latching mechanism for a VHS videocassette which is said to be easier to assemble and less expensive than prior 2-piece mechanism.
Some VHS videocassettes that have recently appeared on the market employ a latching mechanism consisting of a single piece of molded plastic such as shown in U.S. Pat. No. 4,466,583 (Giannis et al.). Although such a latching mechanism simplifies assembly and should be significantly less expensive, its plastic spring member, the "elongate resilient arm 60" of FIGS. 1-5, is under compression when the door is closed as can be seen by comparing FIGS. 7 and 8. Because any plastic member will experience plastic flow or creep if kept under compression, the arms 60 and 68 should gradually lose their effectiveness as spring members, especially in warm weather.
We are not aware of any simplification of the 2-piece latching mechanism of the Betamax videocassette, the latch of which is formed with an inclined plane which, upon being contacted by the aforementioned finger of the recorder, is depressed to unlock the door.